Pool Water Balancing

[KCD]

I'm doing a "what if" evaluation for the upcoming season and need the expertise of the board members. Your inputs are appreciated.
When adding 56 oz of 20 Mule Team Borax to raise the pH from 7.2 to 7.6, how much will the TA (60) and CH (70) levels increase?
When adding 12 lbs of baking soda to raise the TA from 60 to 100, how much will the pH (7.6) and CH (70) levels increase?
When adding 33 lbs of calcium chloride to raise the CH from 70 to 250, how much will the pH (7.6) increase?
When adding 5 lbs of stabilizer to raise the CYA from 0 to 30, how much will TA and pH decrease?

 

[Newdude]

Hey KC !!! Open up the poolmath app or download it (free) if you haven’t already. If you are new you need to set up your pool profile so it knows what you got.

on the main page of the app click the ‘hamburger’ menu in the upper left corner. Select ‘effects of adding’ and go buck wild until your heart is content.

 

[KCD]

The app answered 2 out of 7, the increase in TA level from adding borax and the increase in pH from adding baking soda. Thanks. Five more to go.

 

[Newdude]

Perhaps you would benefit from the in-house App/Bot that we affectionately call @mknauss.

 

[mknauss]

Ha!
If the app does not show an effect, it is not significant.

 

[KCD]

I found another answer on the app: adding 5 lbs of solid stabilizer will decrease the pH by 0.6, which is most significant by far and will probably result in adding a pH reducer.

That leaves four unanswered by the app; but they should have negligible impact; so, pH will not change significantly by adding 33 lbs of calcium chloride, and neither will CH by adding 56 oz of borax, 12 pounds of baking soda, and 5 lbs of CYA.

 

[KCD]

My bad, decrease in pH by 0.6 will likely result in needing to add more borax to increase pH.

 

[mknauss]

My bad, decrease in pH by 0.6 will likely result in needing to add more borax to increase pH.

Not likely. Normal amounts of stabilizer addition will rarely drop the pH below 7. And most pools have a TA of greater than 50 ppm and thus the pH will recover quickly.

 

[KCD]

Or aeration instead to raise pH if the TA is high enough.

 

[KCD]

Not likely. Normal amounts of stabilizer addition will rarely drop the pH below 7. And most pools have a TA of greater than 50 ppm and thus the pH will recover

How long does pH take to recover on its own without adding borax? My assumption is that TA is 100 ppm and pH is 7.1 after stabilizer addition.

 

[mknauss]

With a TA of 100, a few hours to a day or two if you have any aeration (including wind). And a pH of 7.1 is fine. No reason to use chemicals to intervene.

 

[KCD]

My understanding is that solid CYA (sock in a skimmer) takes days to dissolve, so I am assuming there is enough time for aeration to maintain safe pH levels as the CYA level is being raised from 0 to 30.

 

[mknauss]

It can take a while. Squeezing the sock once it has been in the water for a few hours will speed the process.